概要

Cells of Nitella axilliformis were made tonoplast-free by intracellular perfusion of media containing ethyleneglycol-bis-(β-aminoethylether)N,N'-tetraacetic acid (EGTA). When the perfusion medium contained ADP as well as ATP, the membrane hyperpolarized in darkness in a manner similar to light-induced hyperpolarization. This light-independent hyperpolarization seems to be due to activation of the electrogenic ion pump in the plasma membrane because the hyperpolarized value of the membrane potential was more negative than the equilibrium potential for K^+, the most negative ion equilibrium potential in Nitella. The hyperpolarization was inhibited by the respiratory chain inhibitors NaCN (1 mM), antimycin A (10 μM) and rotenone (10 μM). NaCN slightly decreased the ATP concentration in the cell perfused with medium containing 1 mM ATP and 1 mM ADP; but, even after treatment with NaCN, the cell had about 80% of the ATP value for the control.

著者

MIMURA Tetsuro
Department of Biology, Graduate School of Science, Kobe University

新免 輝男
Department Of Life Science Faculty Of Science Himeji Institute Of Technology